Despite what their name might suggest, some firefighters do more than fight fires, they also respond to emergencies that occur in water. These particular firemen are nicknamed "frogmen."

Niu Zixiang, 27, is a member of the Special Duty Team at the No. 1 Station of the Taiyuan Fire and Rescue Department in north China's Shanxi Province. As a professional diver, his main job is conducting underwater rescues in rivers and lakes.

In the past seven years, he has carried out more than 150 missions. And most of his work involves retrieving drowned bodies. Though many would be scared by this, Niu has his own way to overcome the fear.

"Sometimes, I'm scared, too. But I tell myself I'm helping them. So why should I be afraid," Niu said, adding though the job often involves death, he feels duty-bound to get his job done.

"Whether they're alive or not, we always try our best to bring them back. If they have passed away, we must pull them out from the dark waters and return them to their families. It's a comfort for their families."

Searching for people in cold, dark and muddy waters with a cylinder weighing more than 30 kilograms makes his job extraordinarily challenging.

"When the water is cold, you breathe very quickly. And it's dark, so you can barely see, even when you have a light with you," Niu said. "There are often fishing nets, iron nets or plants around you. The river bottom can be uneven, and there can be rapid undercurrents."

The harsh working condition means saving other people's lives often puts his own life at risk. Niu recalled that once in a rescue, his diving equipment got stuck deep down in a narrow stone wall. If he couldn't get out in time, the cylinder would run out of air, which would be very dangerous.

"Luckily, my colleague successfully helped me out, but I had to leave my diving equipment behind," Niu said.

Niu suffers from arthritis after years of work. But he said he doesn't have any regrets. As a member of the Communist Party of China, he said he has to take the lead and rush to the front line in every rescue.

"Whenever people applaud our rescue efforts, I feel everything we've done is worth it," Niu said.

Though Niu is a divemaster, he continues to learn and aims to become a dive instructor. He believes that only if he keeps learning and improving his skills, can he better save lives and ensure his own safety.

"Nothing is more important than life," he said.